1. Field of the Invention
The present invention relates, in general, to a diamond cutting wheel and, more particularly, to a diamond cutting wheel, which is capable of reducing frictional resistance, maximizing cutting efficiency, preventing undesirable chippings from being formed on the cut surface of the workpiece and allowing cut chips to be discharged effectively, by means of a plurality of depressions formed on its cutting tip and the continued cutting surfaces of the cutting tip.
2. Description of the Prior Art
In general, a diamond cutting wheel used to cut stone workpieces, such as structural and engineering asphalt, ash concrete or green concrete, is fabricated by welding a continuously formed cutting tip, which is formed by mixing diamond powder and metallic powder and sintering the mixture, along the circumferential edge of a core disk.
When such a diamond cutting wheel begins to cut a workpiece, the cutting tip of the diamond cutting wheel is brought into contact with the workpiece completely because the cutting tip is continuously formed in the shape of a ring, thereby improving the cutting efficiency of the cutting wheel.
In the utilization of the diamond cutting wheel, when the diamond cutting wheel cuts a workpiece while being rotated at a low speed, frictional resistance exerted on the cutting wheel from the workpiece is small, thereby improving the cutting efficiency of the cutting wheel.
On the other hand, when the diamond cutting wheel cuts a workpiece while being rotated at a high speed, frictional resistance exerted on the cutting wheel is large, thereby deteriorating the cutting efficiency of the cutting wheel.
In other words, when the diamond cutting wheel cuts a workpiece at a high rotating speed, load exerted on the cutting wheel is enlarged and the cutting efficiency of the cutting wheel is lowered because frictional resistance exerted on the cutting wheel is enlarged.
In order to overcome the shortcomings of the conventional diamond cutting wheel, cutting wheels of various shapes have been proposed. FIG. 1 discloses a diamond cutting wheel in which a plurality of separating slots 12 are radially formed on the circumferential end of a core disk 10 and a plurality of cutting tip segments 20xe2x80x2 fabricated by mixing diamond powder and metallic powder and sintering the mixture are welded to the circumferential edge of the core disk 10 separated by the separating slots 12.
In the case of this conventional diamond cutting wheel, since the cutting tip segments 20xe2x80x2 are separated, that is, a gap 2 is formed between each two neighboring cutting tip segments 20xe2x80x2, the contact surface between the cutting wheel and a workpiece is reduced while the cutting wheel cuts the workpiece, thereby reducing load exerted on the cutting wheel and improving the cutting efficiency of the cutting wheel.
However, the side edges of the cutting tip segments 20xe2x80x2 are sharp, so that the side edges generate chippings on the cut surfaces of the workpiece and cause the cutting tips segments 20xe2x80x2 to be damaged by the workpiece.
In FIG. 2, there is depicted another diamond cutting wheel in which a cutting tip 20xe2x80x3 is welded to the circumferential edge of a core disk 10 and a plurality of depressions 3 are formed along the cutting tip 20xe2x80x3 while being regularly spaced from one another. In comparison with the diamond cutting wheel of FIG. 2, this diamond cutting wheel has a superior strength because the cutting tip 20xe2x80x3 is fabricated in the form of a single body. However, since the cutting surfaces of the cutting tip 20xe2x80x3 brought into contact with a workpiece are divided into a plurality of segments by the depressions 3 and the sharp edges of the cutting tip 20xe2x80x3 are formed, there still exists a shortcoming in which chippings are generated on the cut surfaces of the workpiece.
In addition, in the proposed diamond cutting wheels of FIGS. 1 and 2, the separating slots 12 and the depressions 3 are designed to discharge cut chips, but the cut chips are not discharged well through the separating slots 12 or the depressions 3 because the cut chips are easily removed from the separating slots 12 or the depressions 3 by centrifugal force generated by the rotating cutting wheel, thereby hindering the cutting operation of the cutting wheel. Accordingly, the cutting efficiency of the cutting wheel cannot be maximized.
Furthermore, in the proposed diamond cutting, since the radially inner portions of the cutting tip segments 20xe2x80x2 and the radially inner portion of the cutting tip 20xe2x80x3 are respectively and simply fitted around and welded to the circumferential ends of the core disks 10 while being overlapped with the circumferential ends of the core disks 10, the cutting tip segments 20xe2x80x2 and the cutting tip 20xe2x80x3 may be easily removed from the core disks 10 and, particularly, the possibility of the removal of the cutting tip segments 20xe2x80x2 and the cutting tip 20xe2x80x3 is maximized. As a result, the strength of the cutting wheel is relatively low, the life span of the cutting wheel is relatively short, and a user may be damaged by the scattering of the broken pieces of the cutting tip segments 20xe2x80x2 or the cutting tip 20xe2x80x3.
Additionally, in the proposed diamond cutting wheels, since the core disk 10 is fabricated in the form of a flat plate, the core disk 10 may be easily deformed by the stress exerted while the cutting wheel cuts a workpiece. Accordingly, precise cutting is not secured by such conventional diamond cutting wheels.
In the meantime, Korean Patent Publication No. 98-19334 discloses a diamond cutting wheel in which a plurality of corrugations are radially formed on a core disk to be extended from the center of the core disk to the circumference of the core disk in order to reinforce the core disk. Since the corrugations are merely radially formed on a core disk, the strength of the core disk is insufficient for various stresses, such as a twisting stress, that is generated while the cutting wheel cuts a workpiece. Accordingly, the cutting wheel has a disadvantage of not being reinforced sufficiently.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a diamond cutting wheel, which is capable of not only reducing frictional force exerted on the cutting wheel due to the frictional resistance produced by a workpiece, but also preventing chippings from being generated on the cut surfaces of the workpiece and maximizing the cutting efficiency of the cutting wheel.
Another object of the present invention is to provide a diamond cutting wheel, which is capable of performing cutting work effectively by the discharge of the cut chips produced while the cutting wheel cuts a workpiece.
A further object of the present invention is to provide a diamond cutting wheel, which is capable of preventing its cutting tip from being removed and damaged during its cutting work by the secure engagement of the cutting tip with the core disk, thereby improving the sturdiness of the cutting wheel and maximizing the safety of the cutting wheel.
Yet another object of the present invention is to provide a diamond cutting wheel, which has a strength to prevent the core disk from being deformed by stresses of various directions, thereby lengthening the life span of the cutting wheel and allowing the cutting wheel to cut a workpiece precisely.
In order to accomplish the above object, the present invention provides a diamond cutting wheel, comprising a core disk and a sintered cutting tip fitted around and welded to the circumferential end of the core disk, wherein a plurality of depressions are formed on the upper and lower cutting surfaces of the cutting tip while being spaced apart from one another, the depressions formed on the upper cutting surface alternating with the depressions formed on the lower cutting surface so as to allow the cutting surfaces to be continued.